Date: Tue, 22 Feb 2005 23:36:21 +0000 (GMT) From: Robert Watson <rwatson@FreeBSD.org> To: Arjan Van Leeuwen <avleeuwen@gmail.com> Cc: current@freebsd.org Subject: Re: Patches to use local APIC timer cause SCHED_ULE panic at boot Message-ID: <Pine.NEB.3.96L.1050222233444.64875G-100000@fledge.watson.org> In-Reply-To: <d86b487305022215086ff6bad6@mail.gmail.com>
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On Wed, 23 Feb 2005, Arjan Van Leeuwen wrote: > > This doesn't look to be specific to the local APIC timer. The softclock > > thread should be on a run queue since it was being preempted to via > > critical_exit(). KTR_SCHED traces would probably be helpful. > > I'm reading up on KTR_SCHED, but before I start trying to do anything > with it, will it be able to do anything useful when the system isn't in > multi-user yet? I understand from > http://www.watson.org/~robert/freebsd/netperf/ktr/ that I'll have to set > some sysctls that don't seem to be loader tunables, and I won't be able > to run ktrdump. One of the things that page fails to document is that you can dump ktr traces from using "show ktr". It won't be fast of clean, since you're likely on a serial console, but since the records are ordered so you see the most recent first, it makes life a lot easier. At 1024 records as the default buffer size, you might want/need to increase it. I'm not sure we support a way to dump ktr traces over firewire, but we might do (and if not, it's probably easy to add). Robert N M Watson
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